PROJECT SUMMARY/ABSTRACT The comorbidity between major depressive disorder, one of the most prevalent psychiatric conditions, and substance use represents a significant public health concern and a research priority for NIDA.1-7 Nevertheless, the role of mental illness stigma (i.e., social devaluation and rejection associated with one's psychiatric diagnosis) as a risk factor for substance use among individuals with depression remains under-examined. In addition to hindering treatment seeking and recovery,8-14 contending with stigma-related stress depletes self- regulatory resources and can thus lead to emotion dysfunction (i.e., intense, prolonged negative affect and maladaptive emotion regulation), a key mechanism underlying both depression and substance use problems.15? 29 The proposed research utilizes a multimethod approach to explicate the roles of mental illness stigma and co-occurring emotion dysfunction as risk factors for substance use among people with depression, with the goal of informing future efforts to develop targeted substance abuse prevention interventions for this at-risk population. Using 150 adults diagnosed with major depressive disorder with past 30-day substance use, the project will involve: (1) a lab study characterizing the impact of chronic stigma exposure on both physiological and self-report measures of emotion dysfunction in response to a stigma-related emotion induction (i.e., Trier Social Stress Test); and (2) a micro-longitudinal study documenting the concurrent and lagged associations among daily stigma experiences, emotion dysfunction, and alcohol and recreational drug use. The training acquired by the principal investigator, Dr. Peng ?Katie? Wang, through the execution of this interdisciplinary, innovative research project, along with formal coursework, focused workshops, and one-on-one mentorship, will target the following three training objectives: (1) obtain instruction in the physiological assessment of emotional reactivity and regulation, including both cardiovascular and neuroendocrine measures; (2) develop expertise in micro-longitudinal research design, methodology, and data analysis; and (3) acquire skills in conducting research effectively with clinical populations while attending to relevant ethical and safety issues. Dr. Wang will be mentored primarily by Dr. John Pachankis at Yale University, with additional mentoring from Drs. Rajita Sinha (Yale University), Wendy Mendes (University of California, San Francisco), and Bruce Link (University of California, Riverside). Additionally, she will receive methodological and analytical consultation from Drs. Mark Hatzenbuehler (Columbia University) and Jonathon Rendina (Hunter College, City University of New York). Dr. Wang's proposed training through this K01 award will round out her expertise as a social-health psychologist by providing her with the knowledge and skills needed to launch a productive career as an independent research scientist in the field of substance abuse prevention.